iPhone connects and disconnects from Mac

I also had this problem for a long time but trying solutions posted so far such as stopping usbd only worked sometimes. I now have the suspicious the root cause might be that this rapid connect/disconnect only happens when the iPhone is <100% charged so that the iPhone is using the USB connection with PC/laptop to charge itself while trying to use is as real communication link at the same time. Bringing the iPhone 100% charged seems to work OK although the link still flips a few times before settling down. Best would be if anyone knows how to stop the USB connection being used for charging temporarily from PC/laptop or iPhone side.

After struggling with this for way too long I found a youtube vid that provided the solution. I have bookmarked it and, if I could, would send this guy a Christmas Card. Enjoy.

https://youtu.be/CBFMTYjk4eQ

I have a friend with a 2013 MBA and this happened some time ago when I was showing her how to back up her phone to the laptop. At that time the solution was to go to Network settings and remove the phone as a network device. Tried to back up her phone again recently, it kept doing the connect/disconnect but it didn’t show as a network device and no other solution worked, including resetting trust on the phone. Her laptop has another account just for backing up her moms phone, and so I had the thought to log into that account. Sure enough the phone asked if I should trust the computer, I said yes, logged back into my friend’s account and the phone then worked fine. So if no other solution has worked, try creating a new account on the machine and see if the device works like that (if not you may have to reset the trust on the phone first). Hope this helps.

What worked for me; unplugging the cable from the Mac, plugged the cable into the phone first (iPhone 12), then plugged it back into the USB port on the computer, for whatever reason, that corrected it for me. Prior to this quick fix, it did not matter how many times I plugged my phone in, it would just show charging then not charging over and over.

This terminal command also worked for me! Much thanks! I've struggled with this for a long long time! And currently I have a failed battery on my Mid 2015 MBPro Retina so only running off of the external power supply and I can still charge my phone now! Thanks again (in this case to: rpmartins) for providing answers to keep us all going!

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Originally posted by rpmartins:

Try terminal :

sudo killall -STOP -c usbd

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Peace!

slashGW

I had my iPhone doing the same thing, connects and disconnects from Mac, I tried all options mentioned in the forum without lack. Recently I have moved my office to another room and had shut down Mac and disconnect all cables from it, left it off overnight without any cables connected to the Mac, even power cable disconnected from the wall outlet. The next day reconnected all cables and now my phone charges with no problems. I had to Trust my device first.

Alas this did not help me. There is no "iphone USB" option on my Mac.

Tried all methods that you guys left here, still nothing.
Maybe someone know how to solve this issue ?
I have great connect via wifi (Waltr 2, iMazing), but reconnect loop via usb 😟

same here. i have 4 cables and all of them, the same thing happens. keeps connecting and disconnecting. this is not a problem of our phones or computers. im sure its something they did in the os.

This is so frustrating. Tried all of the above. Cahrged an uncharged. It worked a couple of times ... and couple of times it was madness... so annoying.

I've had the same problem for years. MacBook Air and iPhone 8 plus now. I've tried everything, and the only thing that has worked is using a genuine Apple USB cable. What a joke.

I had the same issue. I found that if my phone is fully charged (don't know over which %), and I changed the settings in iTunes to NOT sync automatically, no more rapid disconnecting.

I charged my phone fully, then made the following adjustments to my settings to not sync automatically in iTunes. Now works perfectly.

this worked for me also,

On the mac, go to settings>Network> iphone USB> then uncheck the box that says "Disable unless needed"

Try terminal :

sudo killall -STOP -c usbd

....worked like a charm for me....